Pipe apparatus



July 8, 1969 J. H. FOWLER 3,454,289

PIPE APPARATUS Filed Nov. 7. 1966 Sheet of 2 Jafifl Paw/er INVENTOR.

July 8, 1969 J. H. FOWLER 3,454,289

PIPE APPARATUS Sheet 2 of 2 Filed Nov. 7, 1966 7 c/ofin fbw/r INVENTOR.

United States Patent 3,454,289 PIPE APPARATUS John H. Fowler, Houston, Tex., assignor to Rockwell Manufacturing Company, Houston, Tex., a corporation of Pennsylvania Filed Nov. 7, 1966, Ser. No. 592,543 Int. Cl. F161 21/00 U.S. Cl. 285144 Claims ABSTRACT OF THE DISCLOSURE Emergency situations arise in petroleum drilling operations whereby a pipe string may become stuck before the hanger to which it is attached reaches its support location within the wellhead. In such a situation emergency slip hangers are normally attached around the pipe string just above the wellhead and below the last collar joint, then dropped into place. This is extremely difficult in underwater wellheads, in that it requires a diver. The subject invention presents a slip hanger which may be installed by a remote hanger setter near the wellhead or which may be dropped from the drilling platform to its support. It is so constructed that it will pass intervening collar joints. Thus, the need for a diver is eliminated.

This invention is related to pipe suspension apparatus and more particularly to pipe hangers of the slip type for emergency use in underwater drilling operations.

Many types of hangers have been used in oil and gas wells for suspending casing or tubing within the wellhead. Most of the hangers are attached to the pipe to be suspended and lowered along with the pipe string into position for seating within the wellhead. It is necessary to determine closely where the bottom of the pipe string will be located in order to know where the hanger is to be attached to the string. This is particularly true in underwater wells with Wellheads supported at the mudline. Since several joints of pipe may be attached above the hanger before the hanger reaches the wellhead, a miscalculation would necessitate partially pulling the string to disconnect and relocate the hanger. This, of course, results in lost time and increased expense.

It is not often that hanger location is miscalculated. Occasionally, however, a pipe string may stick before it has been lowered fully in place. Since the normally connected hangers have not reached the wellhead, means must be provided to suspend the pipe string other than the attached hanger. Slip type hangers have been used for these emergencies since they do not depend on the presence of a joint. The major problem, however, of installing an emergency slip type hanger is to find a way to get the hanger into the head. Since collars, and sometimes connected hangers, are between the drilling platform and the head, the normal slip hanger cannot be lowered into position. A diver may be required to install the slip hanger below the last joint prior to the head. This presents major problems, especially in deep water locations.

The present invention solves this problem from two approaches. The first solution is to provide an emergency hanger setter attached near the wellhead in which a special slip type hanger is located. The hanger is split in half and may be remotely installed if the need arises. If not used, the hanger may be removed along with its set ter. The hanger comprises a bowl with slip segments mounted therein. The minor internal diameter of the bowl is less than a collar connection of the pipe to be suspended and the major external diameter of the bowl is less than the internal diameter of all other well equipment connected above the wellhead below the point where the hanger is placed around the pipe. Thus, the hanger is free to drop into the wellhead without fear of its engaging any intervening collars on the pipe for suspension or the wall of any well equipment through which it passes. The second solution is to use the same or similar special slip type hanger which may be installed at the drilling platform and dropped past intervening couplings through a riser and other throughbore well equipment to seat in the wellhead. In this solution, the slip type hanger would not pass a hanger connected to a joint. Therefore, when sticking is anticipated the regular joint connected hanger would not be used. Instead, the slip type hanger alone would be depended on for suspension.

It is, therefore, a primary object of the invention to provide an emergency slip type hanger which may be remotely installed in an underwater well to suspend a stuck casing.

Another object of the invention is to provide a slip type hanger which may be lowered past collar connections to beseated within a wellhead.

Preferred embodiments of the subject invention by which the foregoing objects and other objects are attained are shown in the accompanying drawings and following description. Reference is now made to the accompanying drawings wherein:

FIGURE 1 is an elevation, partially in section, of one embodiment of the invention installed in a remote hanger setter;

FIGURE 2 is an elevation, partially in section, of the embodiment of FIGURE 1 partially seated within a wellhead;

FIGURE 3 is a plan view partially in section, of the embodiment of FIGURE 2, showing the slip segments mounted in the split bowl.

FIGURE 4 is a vertical sectional view of the slip segments and slip bowl of FIGURE 3, taken along line 4-4 of FIGURE 3;

FIGURE 5 is a detailed sectional view of a form of latch device by which the split bowl of FIGURES 3 and 4 may be connected;

Referring first to FIGURE 1, an underwater casing head 1 is shown with a remote connector 5 attached thereto. Remot connector 5 is used to remotely connect control equipment above casing head 1 for drilling operations. It may later be removed for further operations. Above remote connector 5, remote casing hanger setter 7 and other well control equipment such as blowout preventers 11 and pipe user 13 are attached. A portion of a casing 2 is shown being lowered into the well.

Hanger setter 7 is shaped similar to a valve body with a vertical throughbore communicating with blowout preventer 11 and remote connector 5. Hanger setters generally are known in the art, being shown, for example, in U.S. Patents 3,017,931 and 2,002,539. At each end of the body of hanger setter 7 a hydraulic ram 9 is provided. Ram 9 includes a piston 8, rod 10, cylinder 12 and connection block 14. One-half of a split emergency slip hanger 20, to be explained later in detail, is connected to block 14 at each end of the hanger setter 7. If hanger 20 is needed, pressure is supplied to ram 9 through hydraulic conduit 16, forcing piston 8 and connection block 14 inwardly. The two halves of the bowl of slip hanger 20 are latched together. Block 14 is retracted by reverse movement of piston 8, allowing hanger 20 to fall into place within wellhead 1. The slips of hanger 20 engage casing 2, providing support for suspension.

The same slip hanger design may be used without a remote hanger setter by dropping the hanger from the drilling platform around casing 2 and through user 13 to wellhead 1. However, this procedure may only be used if no joint type hangers are connected between the drilling platform and wellhead. Although the hanger is de- Patented July 8, 1969 I signed to by-pass collar connections, larger obstructions may prevent its passage.

Referring now to FIGURE 2, hanger 20 is dropped into wellhead 1, with its slip segments 40 at their uppermost position within hanger bowl 60. In this position the inside diameter of the slip segments 40 is no less than the minor inside diameter of th bowl 60. The minor inside diameter of bowl 60 is greater than the diameter of collar connection 3. The major diameter of the bowl 60 and slip segments 40 at their uppermost position is less than the internal diameter of any pipe or equipment through which they must pass to reach wellhead 1. The major diameter of bowl 60 is no greater than the diameter of collar connection 3 plus twice the maximum thickness of slip segments 40 which in this case is the difference in the major outside and minor inside diameters. Thus, the least amount of annular space is occupied by hanger 20, allowing it to drop through the annular space around casing 2 and to by-pass collar 3 attached to casing string 2. The bowl 60 of hanger is stopped by circumferential shoulders 4 or 6 Within wellhead 1. Slip segments 40 continue moving downwardly and inwardly on taper 66 in the bowl to finally engage casing 2 for suspension support.

Referring now to FIGURES 3 and 4, a preferred embodiment of slip bowl 60 is described in detail. The bowl is generally cylindrical on its exterior. A larger diameter upper portion 61 is joined to lower portion 62 by downwardly facing frusto-conical shoulder 64. The reduction in diameter is merely to reduce material and weight of the bowl. The base of bowl 60 and shoulder 64 will provide cooperative support surfaces with shoulders 4 and 6 within wellhead 1 (see FIGURE 2). The interior surface of bowl 60 forms an inverted frustum of a cone, i.e. it is tapered downwardly. This surface 66 will provide a cooperative wedging surface for the slips to be later described. Wedging surface 66 terminates in a cylindrical band 68 at the base of the bowl. The minor inside diameter of bowl 60 is greater than the diameter of the collar for the particular size pipe string to be suspended. The major outside diameter of bowl 60 is less than the internal diameter of any pipe or equipment through which it must pass to reach its wellhead support position. Bowl 60 is split into halves to facilitate mounting around a pipe.

To connect the halves of bowl 60' together a spring latch device shown in FIGURE 5, is provided. At the base of each half of bowl 60 near one split face 63, a vertical hole 70 is drilled. A horizontal hole 72 is drilled from the exterior of the adjoining half through and perpendicular to the adjacent split faces so that the horizontal hole 72 communicates with vertical hole 70. An inwardly biased spring plunger 71 is mounted in hole 70 so that the end of the plunger extends into hole 72. A latch pin 73 is inserted into hole 72. Latch pin 73 has a downwardly facing beveled face 74 at its end and a downwardly facing slot 75. Slot 74 registers with plunger 71 on the complete abutment of bowl halves 60. Thus, a latch device is provided at the split faces of each half of bowl 60. To engage the latch, the bowl halves are simply moved together, pin 73 being aligned with hole 72. As the beveled face 74 of pin 73 contacts plunger 71, the plunger is downwardly depressed. On complete engagement of pin 73, slot 75 registers with plunger 71 which springs into the slot preventing separation of the split halves of bowl 60. To release the latch, plunger 71 is removed or pin 73 is rotated, camming plunger 71 downwardly.

Bowl 60 is also preferably provided with vertical guide slots 82 machined at, for example, 90 degree intervals, to act as guides for slip segments 40, to be later explained. The exterior of bowl 60 is vertically milled at each one of these slots 82 to provide an inclined surface 84 parallel to interior surface 66. Surface 84 provides a sliding surface for the head of pin 85 which is inserted through slots 82 into slip segments 40. Pin 85 alsolimits the upward movement of the slip segments 40 to retain them against displacement from the bowl 60.

If the hanger is to be used with a remote hanger setter such as 7 in FIGURE 1, a connection slot 86 is machined at the upper edge of each half of bowl 60. Clevis holes 88 are drilled horizontally from the exterior of bowl 60- into slot 86. To connect each half of bowl 60 to the remote hanger setter a portion of connection block 14 (FIG- URE 1) is inserted in connection slot 86. A shear pin (not shown) is inserted through clevis holes 88 into a cooperative hole in connection block 14. Also provided are holes 87 drilled through the bowl 60 below connection slot 86. Pins 89 attached to connection block 14 may be inserted through these holes to support slip segments 40, holding them at their uppermost position within bowl 60 while the bowl is supported by the connection blocks.

To connect the split halves of hanger 20 remotely, the remote hanger setter rams are forced together hydraulically. The spring latch devices previously described and shown in FIGURE 5 are engaged latching the bowl halves together. To release the hanger from the remote setter, reverse direction of the rams causes the shear pins inserted into clevis holes 88 and connection block 14 to be sheared. Thus, the hanger is free to drop into place below.

Referring also to FIGURES 3 and 4, a preferred embodiment of slip segments 40- will be described. Slip segments 40 may be conveniently made from a hollow cylinder. Threads 42 are machined on the interior to provide upwardly directed teeth to engage the supported casing. The exterior is conical in shape, forming a wedge surface to cooperate with the interior wedge surface of bowl 60. The outer face of slips 40 may be provided with downwardly directed teeth 44, if desired, to limit radial loading of the bowl 60, as described, for example, in US. Patent No. 2,887,754 to Johnson. The finished cone is then cut into four segments, slightly less than ninety degrees each. A hole 46 is drilled in each segment perpendicular to wedge surface 44. A guide pin 85, previously described, is inserted through guide slots 82 in bowl 60 into a press fit with hole 46. To assure that all segments move in unison within bowl 60, an alignment rod 54 is threadingly connected to the split wall of each segment perpendicular to the split wall face at threaded hole 48. The rod slidingly projects into a concentric hole 50 in the split wall face of the adjacent slip segment. This allows slip segments 40 to move to their uppermost position within bowl '60 in unison although they are separated. A countersunk entrance 52 to hole 50 assures the alignment rod entrance into hole 50 when the hanger, separated into halves, is brought together for latching.

Referring once again to FIGURE 2, the operation of hanger 20 will be described again. After the split halves of bowl 60 are latched together, either by remote hanger setter or at the drilling platform, hanger 20 drops into wellhead 1. The slip segments are free to slide upwardly with respect to the bowl 60 while the hanger is dropping downwardly, therefore if the segments encounter a collar or the like, they can slide up to increase the opening therethrough and therefore can pass on by the collar. Slip segments 40 are maintained at the same level by alignment rod 54 and concentric holes 48 and 40. When bowl 60 reaches shoulders 4 and 6 within wellhead 1, the bowl comes to a stop. Slips 40 then continue moving downwardly under their own weight and momentum, and are carried radially inwardly due to the cooperating wedge surfaces 44 and 66, thereby causing teeth 42 to engage the exterior of casing 2. A slight downward movement of the casing will seat the slips so that the casing is supported. Thus, it can be seen that emergency suspension may be attained without the necessity of partially pulling a string or dispatchng divers to install a hanger within the wellhead.

I claim:

1. Pipe hanging aparatus for suspending pipe, nected by collar joints of a diameter greater than said pipe, in a wellhead directly above which other through bore well equipment is attached comprising:

tubular bowl means having a generally cylindrical exterior, a downwardly uniformly converging interior, the minor inside diameter of which is greater than said collar joints, and support means thereon to support said apparatus in said wellhead, and

slip means slidably disposed and guided on the interior of said bowl-means by retainer means for limited vertical movement so that at its uppermost position within said bowl means said slip means does not inwardly penetrate said collar joint diameteror outwardly penetrate said internal diameter-of said other well equipment, the major diameter of said bowl means being no greater than said collar joint diameter plus twice the maximum wall thickness of said slip means, said slip means being adapted to move inwardly and downwardly from said uppermost position on said uniformconverging interior to engage said pipe for support thereof.

2. The combination of claim 1 in which said bowl means and said sli'p means are separable into at least two split portions to allow mounting around a pipe, said split portions being joined by latch means, said latch means being automatically engageable on the abutment of said split portions.

3. The combination of claim 2, and including remotely operable setter means comprising a body portion, a vertical throughbore, and piston means movable perpendicularly to the axis of said throughbore, one of said split portions being mountable at each end of said body portion, and

pressure means to cause said piston means to move said split portions in abutment to automatically engage said latch means.

4. A pipe hanger for suspending pipe in a wellhead directly above which other throughbore well equipment is attached comprising: 1

tubular bowl means having a generally cylindrical exterior, a downwardly converging frusto-conical interior, the minor diameter of which is greater than the collar joint diameter of the pipe string to be hung by said pipe hanger, and means for supporting said hanger in said wellhead,

segmented sl-ip means slidingly disposed within said bowl means, the inner faces of said slip means being generally cylindrical in shape and having pipe engagement means thereon, the outer faces of said slip means being defined by a uniformly tapered surface cooperating with said frusto-conical interior of said bowl means to cause said slip means "to be wedged into engagement with said pipe for suspension of said pipe string, and

cooperative guide means to slidingly guide and retain said slip meahs within said bowl means, said guide means to allow said slip means to be moved upwardly within said bowl means before engagement with said pipe so that said inner faces of said slip means do not lie within said collar joint diameter nor said outer faces without said internal diameter of said other well equipment, the major diameter of said bowl means being no greater than said collar joint diameter plus twice the maximum distance between said slip means inner and outer faces.

5. Pipe suspension apparatus comprising:

a tubular wellhead having at least one upwardly facing shoulder therein above which other throughbore well equipment is attached.

a split tubular hanger bowl having at least one downwardly facing surface to contact said wellhead internal shoulder for support thereon, the interior of said hanger bowl converging downwardly in a tapered surface, the diameter of an included circle at the base of said tapered surface being greater than the diameter of a collar joint of the pipe string to be suspended by said pipe suspension apparatus, said collar joint diameter being greater than said pipe diameter,

a plurality of slip segments slidingly disposed and retained within said hanger bowl, said-slip segments having outer faces downwardly converging in a tapered surface, the inner faces of said slip segments conforming to the shape of a portion of a cylinder with pipe engagement means thereon, said slip segments being movable to an upper position within said bowl so that the outer faces of said slip segments do not interfere with the internal diameter of said other well equipment and so that the diameter of an included circle within said inner faces is no less than said diameter of said collar joint, said slip segments to move uniformly downwardly and inwardly along said hanger bowl tapered interior to wedgingly engage said pipe for suspension thereof, the major diameter of said bowl means being no greater than said diameter of said collar joint plus the difference between saidslip segments major outside and minor inside diameters.

6. A pipe hanger means for suspending pipe in a wellhead above which other throughbore well components are attached comprising:

annular bowl means, the interior of said bowl means being an upwardly facing frusto-conical surface the minor diameter of which is greater than the diameter of an enlarged diameter collar joint of the pipe string to be hung by said pipe hanger, the exterior diameter of said bowl means being less than the internal diameters of said other well components, support means on said bowl means for supporting said pipe hanger within said wellhead,

slip means slidingly disposed within said bowl means, said slip means including slip segments, the outer faces of said slip segments forming a portion of a frustum of a cone, the inner faces of said slip segments forming a portion of a cylinder, the inner faces of said segments having upwardly facing teeth thereon,

cooperative guide means including vertical grooves through the sidewall of said bowl means and guide pins slidingly retained in said grooves, said guide pins being fixedly attached to said sl-ip segments, said cooperative guide means to allow said slip segments limited movement upwardly and outwardly within said bowl means so the inner faces of said slip segments do not inwardly penetrate said collar joint diameter and the outer faces do not outwardly penetrate said internal diameters of said other well components, said cooperative guide means to allow said slip segments to move downwardly and inwardly to engage said teeth thereon with a pipe for suspension, and

alignment means laterally connected between said slip segments to assure unison of vertical movement within said bowl means.

7. Remotely operable apparatus for suspending pipe in a wellhead located on the floor of a body of water and above which is afiixed other throughbore well equipment comprising:

[tubular bowl means with support means thereon for supporting said apparatus within said wellhead, the minor internal diameter of said bowl means being greater than the diameter of a coupling for said P P a plurality of pipe support segments, slidingly disposed and retained in said bowl means by guiding means, having inwardly facing means adapted to engage said pipe,

said segments being movable radially outward to a position such that no part of any segment extends inwardly far enough to intersect a circle defining the diameter of said coupling for said pipe nor outwardly far enough to intersect the internal diameter of said other well equipment yet capable of outwardly penetrating a diameter equal to the external diameter of said bowl means,

and vertical alignment means extending between said segments to prevent said segments to be displaced vertically with respect to each other when the segments are being moved vertically toward pipe e11- gaging position.

8. Pipe hanging apparatus according to claim 1 where- 4 in said other throughbore well equipment comprises a substantially vertical pipe riser.

9. Remotely operable apparatus according to claim 7 wherein said other throughbore well equipment comprises a riser connected to said wellhead and extending upwardly through said body of water.

10. Remotely operable apparatus according to claim 9 wherein said bowl means external diameter does not exceed the internal diameter of said riser so that said bowl means and said segments are capable of passing [through said riser around intervening pipe couplings into 2 said wellhead support position.

UNlTED References Cited STATES PATENTS Shaw 24-2635 Burns 24-26315 Montgomery 24-2635 Young 24-2635 Segelhorst 285-145 Barker 285-145 Lundeen 24-2635 Neilon 24-2635 X Jackson 285-144 X Watts 24-2635 X CARL W. TOMLIN, Primary Examiner. DAVE W. AROLA, Assistant Examiner.

- US. Cl. X.R. 

